What's worse, CdeeZ, isn't the bearing staining, it's the surface shear failure in that same photo. Look on the gear teeth at 8 and 9 o'clock, you see those tiny pits on the involute face? That is the material failure. They will only get worse, and there's nothing you can do to fix them. Maybe it's just dirt, but to me, that's the textbook pitting of a surface shear failure.
Same thing happens in a flat tappet cam when you don't have enough EP lube in the oil, or the valve spring pressure is too high, or you're just running much too aggressive a profile on the cam lobe. The lube gets forced out and you get metal-on-metal right there in a tightly focused area, which results in the hard surface literally tearing off the softer core-thus "surface shear" failure. Ways to fix that issue is use a lube with more phosphorus or sulfur, although I think boron compounds are the new hotness in EP additives.
Could also be that the oil was fine, but just breaking down from the same heat that stained those bearing rollers. Do you have more photos of similar detail on the countershaft gears?
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